<template>
  <div>
    <!-- 评论列表 -->
    <div class="cmt-list" :class="{ 'art-cmt-container-1': isShowCmtBox, 'art-cmt-container-2': !isShowCmtBox }">
      <van-list v-model="loading" :finished="finished" finished-text="没有更多评论了" @load="onLoad" :immediate-check="false">
        <!-- 评论的 Item 项 -->
        <div class="cmt-item" v-for="obj in commentArr" :key="obj.com_id">
          <!-- 头部区域 -->
          <div class="cmt-header">
            <!-- 头部左侧 -->
            <div class="cmt-header-left">
              <img :src="obj.aut_photo" alt="" class="avatar" />
              <span class="uname">{{ obj.aut_name }}</span>
            </div>
            <!-- 头部右侧 -->
            <div class="cmt-header-right">
              <van-icon name="like" size="16" color="red" v-if="obj.is_liking === true" @click="likeFn(true, obj)" />
              <van-icon name="like-o" size="16" color="gray" v-else @click="likeFn(false, obj)" />
            </div>
          </div>
          <!-- 主体区域 -->
          <div class="cmt-body">
            {{ obj.content }}
          </div>
          <!-- 尾部区域 -->
          <div class="cmt-footer">{{ timeAgo(obj.pubdate) }}</div>
        </div>
      </van-list>
    </div>

    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShowCmtBox === true">
      <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="toggleShowFn">发表评论</div>
      <div class="icon-box">
        <van-badge :content="totalCount === 0 ? '' : totalCount" max="99">
          <van-icon name="comment-o" size="0.53333334rem" @click="commentClickFn" v-if="isShowNews" />
          <van-icon name="comment" color="#1C86EE" size="0.53333334rem" v-else />
        </van-badge>
        <van-icon name="star-o" size="0.53333334rem" v-if="isShowStar" @click="starOFn" />
        <van-icon name="star" color="#FFD700" size="0.53333334rem" v-else @click="starFn" />
        <van-icon name="share-o" size="0.53333334rem" @click="showShare = true" />
      </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea placeholder="友善评论、理性发言、阳光心灵" v-fofo @blur="blurFn" v-model.trim="comText"></textarea>
      <van-button type="default" :disabled="comText.length === 0" @click="sendFn">发布</van-button>
    </div>

    <!-- 分享面板 -->
    <van-share-sheet v-model="showShare" title="立即分享" :options="options" @select="onSelect" />
  </div>
</template>

<script>
import { commentsListAPI, commentLikingAPI, commentDisLikingAPI, commentSendAPI, articleCollectionAPI, articleUnCollectionAPI } from '@/api/index'
import { timeAgo } from '@/utils/date.js'
import Notify from '@/ui/Notify'
export default {
  data () {
    return {
      offset: null, // 偏移量评论ID
      commentArr: [], // 评论列表
      isShowCmtBox: true, // 底部容器的显示/隐藏
      totalCount: 0, // 评论总数量（必须后台返回）
      comText: '', // 发布评论的内容
      finished: false,
      loading: false,
      lastId: null, // 分页
      isShowNews: true, // 显示/隐藏消息按钮
      isShowStar: true, // 显示/隐藏收藏按钮
      showShare: false, // 显示/隐藏分享面板
      options: [
        { name: '微信', icon: 'wechat' },
        { name: '微博', icon: 'weibo' },
        { name: 'QQ', icon: 'qq' },
        { name: '复制链接', icon: 'link' },
        { name: '分享海报', icon: 'poster' },
        { name: '二维码', icon: 'qrcode' }
      ]
    }
  },
  async created () {
    this.isShowNews = true
    const res = await commentsListAPI({
      id: this.$route.query.art_id
    })
    this.commentArr = res.data.data.results
    this.totalCount = res.data.data.total_count // 总数量
    this.lastId = res.data.data.last_id // 分页

    // 刚一加载就没有评论
    if (res.data.data.last_id === res.data.data.end_id || res.data.data.last_id === null) {
      this.finished = true
    }
  },
  methods: {
    timeAgo,
    async likeFn (bool, obj) {
      if (bool === true) {
        // 用户点在了红心身上 -> 显示灰色的心
        obj.is_liking = false
        await commentDisLikingAPI({
          comId: obj.com_id
        })
      } else {
        // 用户点在了灰色的心身上
        obj.is_liking = true
        await commentLikingAPI({
          comId: obj.com_id
        })
      }
    },
    // 显示 -> 评论输入框 (第二套 - 高)
    toggleShowFn () {
      this.isShowCmtBox = false
    },
    // 页面滚动变换消息图标
    handleScroll () {
      if (document.querySelector('.cmt-list')) {
        const scrollTop = window.pageYOffset
        const offsetTop = document.querySelector('.cmt-list').offsetTop - window.screen.height
        if (scrollTop <= offsetTop) {
          this.isShowNews = true
        } else {
          this.isShowNews = false
        }
      }
    },
    // 评论按钮 -> 点击事件 -> 把第一条评滑动到最上面
    commentClickFn () {
      // // 获取文章的高度
      // const articleHeight = document.querySelector('.article-container').scrollHeight
      // // 使网页滚动文章的高度
      // window.scrollTo(0, articleHeight)
      // 动画实现的JS原生代码,在配置资料扩展-> txt文档里

      // 比较方面的方法(既能滚动,又能带动画),让原生的标签滚动到屏幕的最上面
      // 选择like-box的原因是头部导航会挡住
      document.querySelector('.like-box').scrollIntoView({
        behavior: 'smooth'
      })
      this.isShowNews = false
    },
    // 发布按钮 - 点击事件
    async sendFn () {
      // 把评论加入到列表里
      const res = await commentSendAPI({
        id: this.$route.query.art_id,
        content: this.comText
      })
      this.commentArr.unshift(res.data.data.new_obj)
      this.totalCount++
      this.comText = ''
      this.commentClickFn() // 让第一条评论滚动到屏幕上
    },
    // 输入框 -> 失去焦点
    blurFn () {
      // 问题:点击发布按钮,发现点击事件不执行-排除代码问题
      // 原因:高的屁股论容器-在页面点击发布一瞬间,输入框失去了焦点,被v-if和v-else移除了整个标签,导致了点击事件没来得及执行
      // 解决:失去焦点时,变量值,在最后执行
      setTimeout(() => {
        this.isShowCmtBox = true
      }, 0)
    },
    // 加载更多
    async onLoad () {
      if (this.commentArr.length > 0) {
        // 请求下一个数据
        const res = await commentsListAPI({
          id: this.$route.query.art_id, // 文章id
          offset: this.lastId
        })

        this.commentArr = [...this.commentArr, ...res.data.data.results]
        this.totalCount = res.data.data.total_count // 总数量
        this.lastId = res.data.data.last_id // 分页

        // 结束加载状态
        this.loading = false
        // 加载最后一个时显示结束加载
        if (res.data.data.last_id === res.data.data.end_id || res.data.data.last_id === null) {
          // 没有下一个了
          this.finished = true
        }
      } else {
        this.loading = false
      }
    },
    // 关注文章 - 点击事件
    async starOFn () {
      const res = await articleCollectionAPI({
        artId: this.$route.query.art_id
      })
      if (res.status === 201) {
        Notify({ type: 'success', message: '收藏成功' })
      } else {
        Notify({ type: 'success', message: '收藏失败' })
      }
      this.isShowStar = false
    },
    async starFn () {
      const res = await articleUnCollectionAPI({
        artId: this.$route.query.art_id
      })
      if (res.status === 204) {
        Notify({ type: 'success', message: '取消收藏成功' })
      } else {
        Notify({ type: 'success', message: '取消收藏失败' })
      }
      this.isShowStar = true
    },
    // 分享面板处理函数
    onSelect (option) {
      this.showShare = false
    }
  },
  mounted () {
    // 监听滚动事件
    window.addEventListener('scroll', this.handleScroll)
  },
  destroyed () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}

/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
